Rockwell Automation T3431-CA ICS Regent Thermo Couple Input Assembly - Manual (Page 3)

Thermocouple Input Assembly (T3431)
P D - 6 0 2 4 M a r - 0 6
3
Figure 1. Block Diagram of the Thermocouple Input Assembly.
The Serial data received from the Mux is optically coupled at
the input module to provide electrical isolation. The input
module's 68000-based microcomputer processes the
thermocouple data. This microcomputer’s functions include:
· Digital filtering
·
Automatic calibration
· Cold junction compensation
· Temperature conversion and linearization
·
Diagnostics
The processor modules send triplicated read data requests to
the thermocouple input module over the I/O Safetybus. The
processors’ addressing data and data read requests are voted
by the module (preventing I/O Safetybus failures upstream
from the module from affecting module operations). The voted
result is then passed to the I/O bus interface logic.